Valve amplifier



Feb. 2z; `1927. A H. E. RUKOP VALVE vMIPLIFIER Filed Sept. 3, 1921Snom/woz HANS EWALD RUKOP 3512* his Home/1g Petenfed Feb. 22, 1927.

l 1,618,298 'PATENT OFFICE.

ma' swarm nuxor, or 3mm, annum, AssreNon ro ensnLLscHur naanrnosnrnrmemm 1r. n. n. HaLLnscnns, or Banana, enzym, .a coa- IPORATION 0I'GERMANY.

A vanyn Anrurmn.

application. mea september a, 1921, serial 1re. 499,472, and in Germany,spgm 9, 1917.

(GRANTED 'UNDER THE RROVISIONS 0F THE AUT 0I' ILRGI 3, 1921, 41 STAT.Il., 1818.)

This invention relates to a valve ampliiier inthe form of athree-electrode vacuum tube, and an object of the invention is tolenable the voltage of the grid of the tube 5 to be accurately adjustedto theA optimum value.

In the drawing, p

Fig. 1 shows a vacuum tube arrangement indwhich the invention may beemployed, an

Figs. 2 and 3 show vacuum tube arrangements of slightly dierent formembodying the invention. J

In the operation of an amplifying tube 1iwith a glow4cathode,it isnecessary to 1mpress upon the grid a certain voltage, on the average 2or 3 volts negative, relatively to the cathode. A' simple means to bringabout this negative voltage of the grid with' respect to the cathode isto put a series resistance R into the heating circuit of the cathode andtobranch off therefrom the o grid voltage tobe obtained. and to. thisend there .is provided in parallel with the iron resistance E aresistance -R1 from which the gridconductor is branched oil' and whichis very great compared with the resistance E,

causedyto be always near vthe optimum value, but it is' not absolutelyconstant. since it' is proportional to the voltage at the'ironresistance. This iiuctuation can' be reduced f0- Ato an unnoticeabledegree by placlngbetween the cathode and the iron resistance, a secondconstant resistanceR'2, Fig. 3.

The self-regulating resistance mentwned above, is` a resistance made upof a materialMV whose resistivity rises sharply' with increase incurrent therethrough, therebyv acting automatically as ai currentlimiting device. In thiss'ensethis term is used in the-appended claims.-

Having' deeeribed my iaventien, ,what I vclaim. is:

amplifier comprising a cathode Of course, the grid-voltage may then be"i, iilament and a grid, a self-regulating resistance in theheatingcurrent circuit of the filament, a constant resistance arranged inparallel with said first-mentioned resistance, and a conductor for thegrid connected adjustably to the last-mentioned resistance.

2. A valve amplifier comprising a cathode filament and a grid, a sourceof energy in the heating current circuit of the filament, aself-regulating resistance inserted in said circuit between the filamentand the negative terminal of said source of energy. a

constant resistance arranged in parallel with said iirst-mentionedresistance', and a conductor for the grid connected adjustably to thelast-mentioned resistance.

3. A valve amplifier comprising a cathode allel with saidself-regulating resistance and,

of great value as compared with the selfregulating'resistance. andaconductor for the grid connected withsad last-mentioned resistance. f

4. Avalve amplifier comprising a cathode filamentand a grid.` aself-regulating iron resistance in the heating current circuit of thefilament, a constantresstane'e arranged in parallel with Asaid ironresistance` a conductor -for the grid adiustably connected with thelast-mentioned resistance. and a `second constant resistance arrangedinthe filament heating circuit in series with 'both lof saidtiret-mentioned resistances. l

. 5. A valve amplifier comprising a cathode filament and a grid. aself-regulating iron resistance in the heating current circuit of theilament, a constant resistance arranged in parallel with said ironresistance, a conductor for the grid adjustably connected withthelast-'mentioned resistance and ,a second constant resistance arrangedin the filament heating circuit between the iron resistance and theiilament'and in series with both of saidl first-mentioned resistances.

y -6. -In combination, an electron discharge device having a cathode anda control electrode, va Aself-regulating resistance in the heatingcurrent circuit of said cathode, a 4

` constant resistance arranged in parallel to 'i' tor for the controlelectrode connected to a point on said constant resistance.

7. In combination, an electron Ydischarge device havin a cathode and acontrol elec- 5 trade, a sel -regulating resista-nce in the heatingcurrent circuit of said cathode, a constant resistance in parallel withsaid selfregulating resistance, a conductor for the control electrodeconnected to a point on said constant resistance, and a second con- 10stunt resistance in the heatinrr current circuit in series with bothsaid first-mentioned resstances.

In testimony whereof I aix the signature.

HANS EWALD RUKOP.

